The tension in the East China Sea between China and Japan is America’s problem. Sure, there are all sorts of reasons war will “never” break out — from “it just wouldn’t make sense” to “everybody is making too much money to fight.” But given the history of the region and the lack of rules for handling such crises, the reality is that one stupid mistake could start a war. Since the United States is obligated by treaty to defend Japan if it is attacked, it falls to Washington to make sure a conflict does not erupt.

Over the past several months, Tokyo and Beijing have played a game of chicken, in the streets, on the seas, in the air and through the airwaves over a cluster of three uninhabited islands and two big rocks called the Senkakus by the Japanese and the Diaoyu Islands by the Chinese. Japan seized them in January 1895, during its first modern war with China (which Japan won). Tensions began escalating last year and have grown from anti-Japanese protests in Chinese cities to a war of words to the present situation, in which an increasing number of Chinese and Japanese ships and planes are frequenting a very small area in the East China Sea. The Japanese government announced Tuesday that twice in the past three weeks Chinese warships have upped the ante even further by “painting” a Japanese warship and helicopter with the same type of radar used to aim missiles.

In a region devoid of rules like those that existed between the United States and the Soviet Union when their ships and planes crossed paths, the possibility of a deadly accident is high. In addition to the radar scares, the two sides have exchanged threats, with Japan stating that its fighter jets would fire tracer bullets near Chinese aircraft if they strayed too near the rocks. A retired but influential Chinese army general responded that such an act would constitute a “first shot.”

The new chief of China’s Communist Party, Xi Jinping, has even taken to urging the People’s Liberation Army to “prepare for war.” The last time I heard an official Chinese outlet use that expression was 1980, when I was sleeping in my dormitory room at Nanjing University. A speaker just outside our window would erupt at 6 each morning with a tinny call to “increase vigilance, protect the motherland and prepare for war!” (The enemy then alternated between the Soviet Union and the United States.) Xi’s call was echoed Jan. 15 by the army’s official daily. “Bad habits” occur in the military, one article said, when “there is a lengthy period without war.”

In China, there is an element of bread and circuses going on. The Communist Party is ginning up nationalist resentment against Japan and its ally, the United States, as a way to deflect attention from China’s significant social challenges. While many people here are justifiably proud of their country’s economic rise, they are not happy about a slew of issues, including endemic corruption, polluted air, lack of press freedom, an opaque legal system and sketchy food safety. Diverting the people’s gaze toward a hated neighbor is an easy, if short-term, fix. Chinese tactics toward Japan, dispatching planes and ships to the Senkakus, also mirror Beijing’s behavior toward the Philippines and Vietnam in recent months — actions designed to humiliate and to make the point that the disputed territories are not really under the control of any single country.

Still, Japan is not blameless. The Democratic Party of Japan fell from power late last year partly because of its inability to manage the crisis (although its botching of the country’s economy was more important). The new Liberal Democratic Party government of Prime Minister Shinzo Abe has made the situation no better with its tough talk. When Assistant Secretary of State Kurt Campbell visited Tokyo in January, he said the United States wanted to see “cooler heads prevail” — a clear reference to both Washington’s ally and China. Abe did dispatch an envoy to Beijing for informal talks and has said he is willing to hold a summit with China’s leaders, but it is unclear whether the Communist Party wants to lower the heat.

The problem with this crisis is that it seems insoluble. Japan won’t give the islands back to China, and China can’t back down.

What’s equally troubling is that the United States does not have a stellar record of avoiding war in Asia. In the beginning of the 20th century, Washington helped facilitate the rise of Japan and then sat by as that country took chunks of China, ignoring decades of bad behavior until it was too late and Pearl Harbor was attacked. Today, Washington faces a similarly nettlesome challenge — only this time the roles are reversed. China is resurgent and Japan is relatively frail. The United States needs to find a way to support its friend without alienating Beijing, a tough balancing act, especially when there is an assumption in China that the black hand of America benefits from bad blood between the two neighbors. That is not the case, but if a conflict erupts in the East China Sea, truth will be the first casualty.